Add the cli flag --silent to astro which sets astro and snowpack logging to output nothing (#613)

.changeset/pretty-windows-bow.md

@@ -0,0 +1,5 @@
+---
+'astro': patch
+---
+
+Add command line flag `--silent` to astro to set no output.

packages/astro/src/cli.ts

@@ -78,6 +78,7 @@ function printHelp() {
   --no-sitemap          Disable sitemap generation (build only).
   --reload              Clean the cache, reinstalling dependencies.
   --verbose             Enable verbose logging
+  --silent              Disable logging
   --version             Show the version number and exit.
   --help                Show this help message.
 `);

packages/astro/src/logger.ts

@@ -159,4 +159,11 @@ function padStr(str: string, len: number) {
   return str + spaces;
 }
 
-export const defaultLogLevel: LoggerLevel = process.argv.includes('--verbose') ? 'debug' : 'info';
+export let defaultLogLevel: LoggerLevel;
+if (process.argv.includes('--verbose')) {
+  defaultLogLevel = 'debug';
+} else if (process.argv.includes('--silent')) {
+  defaultLogLevel = 'silent';
+} else {
+  defaultLogLevel = 'info';
+}

packages/astro/src/snowpack-logger.ts

@@ -4,5 +4,7 @@ import { defaultLogLevel } from './logger.js';
 export function configureSnowpackLogger(logger: typeof snowpackLogger) {
   if (defaultLogLevel === 'debug') {
     logger.level = 'debug';
+  } else if (defaultLogLevel === 'silent') {
+    logger.level = 'silent';
   }
 }